Which condition in a pregnant patient with severe pre eclampsia is an indication for administering magnesium sulfate?

Fetal growth restriction Small-for-Gestational-Age (SGA) Infant Infants whose weight is the 10th percentile for gestational age are classified as small for gestational age. Complications include perinatal asphyxia, meconium aspiration, polycythemia, and... read more or fetal death Stillbirth Stillbirth is delivery of a dead fetus at > 20 weeks gestation. Maternal and fetal testing is done to determine the cause. Management is as for routine care after live delivery. Stillbirth,... read more may result. Diffuse or multifocal vasospasm can result in maternal ischemia, eventually damaging multiple organs, particularly the brain, kidneys, and liver. Factors that may contribute to vasospasm include decreased prostacyclin (an endothelium-derived vasodilator), increased endothelin (an endothelium-derived vasoconstrictor), and increased soluble Flt-1 (a circulating receptor for vascular endothelial growth factor). Women who have preeclampsia are at risk of abruptio placentae Abruptio Placentae Abruptio placentae is premature separation of a normally implanted placenta from the uterus, usually after 20 weeks gestation. It can be an obstetric emergency. Manifestations may include vaginal... read more in the current and in future pregnancies, possibly because both disorders are related to uteroplacental insufficiency.

The coagulation system is activated, possibly secondary to endothelial cell dysfunction, leading to platelet activation. The HELLP syndrome (hemolysis, elevated liver function tests, and low platelet count) develops in 10 to 20% of women with severe preeclampsia or eclampsia; this incidence is about 100 times that for all pregnancies (1 to 2/1000). Most pregnant women with HELLP syndrome have hypertension and proteinuria, but some have neither.

Symptoms and Signs of Preeclampsia and Eclampsia

Preeclampsia may be asymptomatic or may cause edema or excessive weight gain. Nondependent edema, such as facial or hand swelling (the patient’s ring may no longer fit her finger), is more specific than dependent edema.

Reflex reactivity may be increased, indicating neuromuscular irritability, which can progress to seizures (eclampsia).

Petechiae may develop, as may other signs of coagulopathy.

Preeclampsia with severe features may cause organ damage; these features may include

• Severe headache

• Visual disturbances

• Confusion

• Epigastric or right upper quadrant abdominal pain (reflecting hepatic ischemia or capsular distention)

• Nausea and/or vomiting

• Dyspnea (reflecting pulmonary edema, acute respiratory distress syndrome [ARDS], or cardiac dysfunction secondary to increased afterload)

• Stroke (rarely)

• Oliguria (reflecting decreased plasma volume or ischemic acute tubular necrosis)

If preeclampsia is diagnosed, tests include complete blood count (CBC), platelet count, uric acid, liver tests, blood urea nitrogen (BUN), creatinine, and, if creatinine is abnormal, creatine clearance. The fetus is assessed using a nonstress test or biophysical profile (including assessment of amniotic fluid volume) and tests that estimate fetal weight.

HELLP syndrome is suggested by microangiopathic findings (eg, schistocytes, helmet cells) on peripheral blood smears, elevated liver enzymes, and a low platelet count.

Preeclampsia with severe features is differentiated from mild forms by one or more of the following:

• Central nervous system (CNS) dysfunction (eg, blurred vision, scotomata, altered mental status, severe headache unrelieved by acetaminophen)

• Symptoms of liver capsule distention (eg, right upper quadrant or epigastric pain)

• Nausea and vomiting

• Serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 2 times normal

• Systolic BP > 160 mm Hg or diastolic BP > 110 mm Hg on 2 occasions ≥ 4 hours apart

• Platelet count < 100,000/mcL

• Urine output < 500 mL/24 hours

• Pulmonary edema or cyanosis

• Stroke

• Progressive renal insufficiency (serum creatinine > 1.1 mg/dL or doubling of serum creatinine in women without renal disease)

Definitive treatment for preeclampsia is delivery. However, risk of early delivery is balanced against gestational age, severity of preeclampsia, and response to other treatments.

Usually, immediate delivery after maternal stabilization (eg, controlling seizures, beginning to control blood pressure [BP]) is indicated for the following:

• Pregnancy of ≥ 37 weeks

• Eclampsia

• Preeclampsia with severe features if pregnancy is ≥ 34 weeks

• Deteriorating renal, pulmonary, cardiac, or hepatic function (eg, HELLP syndrome)

• Nonreassuring results of fetal monitoring or testing

Other treatments aim to optimize maternal health, which usually optimizes fetal health. If delivery can be safely delayed in pregnancies of < 34 weeks, corticosteroids are given for 48 hours to accelerate fetal lung maturity. Some stable patients can be given corticosteroids after 34 weeks and before 36 weeks (late preterm period) if they have not required corticosteroids earlier in the pregnancy.

Most patients are hospitalized. Patients with eclampsia or preeclampsia with severe features are often admitted to a maternal special care unit or an intensive care unit (ICU).

If preeclampsia does not have severe features and occurs before 37 weeks, outpatient treatment is possible; it includes modified activity (modified rest), BP measurements, laboratory monitoring, fetal nonstress testing, and physician visits at least once a week.

However, most patients who have preeclampsia without severe features require hospitalization, at least initially. As long as no criteria for preeclampsia with severe features are met, delivery can occur (eg, by induction) at 37 weeks.

Outpatients are usually evaluated at least once a week for evidence of seizures, preeclampsia with severe features, and vaginal bleeding; BP, reflexes, and fetal heart status (with nonstress testing or a biophysical profile) are also checked. Platelet count, serum creatinine, and serum liver enzymes are measured frequently until stable, then at least once a week.

All hospitalized patients are followed by an obstetrician or a maternal-fetal medicine specialist and evaluated as for outpatients (described above); evaluation is more frequent if preeclampsia with severe features is diagnosed or if gestational age is < 34 weeks.

As soon as eclampsia is diagnosed, magnesium sulfate must be given to prevent seizures from recurring. If patients have preeclampsia with severe features, magnesium sulfate can be given to prevent seizures. Magnesium sulfate is given for 24 hours postpartum. Whether patients who have preeclampsia without severe features always require magnesium sulfate before delivery is controversial.

Magnesium sulfate 4 g IV over 20 minutes is given, followed by a constant IV infusion of about 1 to 3 g/hour, with supplemental doses as necessary. Dose is adjusted based on the patient’s reflexes. Patients with abnormally high magnesium levels (eg, with magnesium levels > 10 mEq/L or a sudden decrease in reflex reactivity), cardiac dysfunction (eg, with dyspnea or chest pain), or hypoventilation after treatment with magnesium sulfate can be treated with calcium gluconate 1 g IV.

IV magnesium sulfate may cause lethargy, hypotonia, and transient respiratory depression in neonates. However, serious neonatal complications are uncommon.

If oral intake is prohibited, hospitalized patients are given IV Ringer lactate or 0.9% normal saline solution, beginning at about 125 mL/hour (to increase urine output). Persistent oliguria is treated with a carefully monitored fluid challenge. Diuretics are usually not used. Monitoring with a pulmonary artery catheter is rarely necessary and, if needed, is done in consultation with a critical care specialist and in an intensive care unit (ICU). Anuric patients with normovolemia may require renal vasodilators or dialysis.

If seizures occur despite magnesium therapy, diazepam or lorazepam can be given IV to stop seizures, and IV hydralazine or labetalol is given in a dose titrated to lower systolic BP to 140 to 155 mm Hg and diastolic BP to 90 to 105 mm Hg.

The most efficient method of delivery should be used. If the cervix is favorable and rapid vaginal delivery seems feasible, a dilute IV infusion of oxytocin is given to accelerate labor; if labor is active, the membranes are ruptured. If the cervix is unfavorable and prompt vaginal delivery is unlikely, cesarean delivery can be considered. Preeclampsia and eclampsia, if not resolved before delivery, usually resolve rapidly afterward, beginning within 6 to 12 hours.

Patients should be evaluated every 1 to 2 weeks postpartum with periodic BP measurement. If BP remains high after 6 weeks postpartum, patients may have chronic hypertension and should be referred to their primary care physician for management.